Synthesis, Structures And Properties Of Pyridyl Substituted Terpyridine Complexes

The design and construction of supramolecular assemblies and polymers based on the use of functionalized terpyridine ligands as building blocks are current interest.This dissertation is aimed to synthesize pyridyl substituted terpyridine luminescent complexes by the reaction of d¹⁰metals (Zn²⁺,Cd²⁺)or strong luminescent lanthanide ions(Eu³⁺,Tb³⁺and Dy³⁺)with 4'-(3-pyridyl)-terpyridine(3-pytpy)or 4'-(2-pyfidyl)-terpyridine(2-pytpy).Four series,22 d¹⁰ transition/lanthanide complexes have been obtained.All of the compounds were characterized by IR,elemental analyses,UV-vis and luminescent spectroscopy.The results are following:(1)We investigated the influence of the positional isomeric effect on structures.Due to the less space-crowding,it is easier for 3-pytpy to behave as bridging ligand than 2-pytpy under the same reaction conditions,while,it is easier for 2-pytpy to function as tridentate chelating ligand to construct supramolecular structures.The successful synthesis of these compounds may provide some new information on the selection of suitable organic building blocks for controllable synthesis of desired species with predictable structures and properties.(2)Based on the "metalloligands as building blocks" synthetic strategy and one-step self-assembly reaction,three heterometallic coordination compounds containing[M(3-pytpy)₂]²⁺ unit were synthesized.This may provide us some ideas for the construction of heterometallic structures.(3)A new family of lanthanide terpyridine nitrate complexes was synthesized.The luminescent spectra indicate pytpy ligands are effective energy sensitizers for luminescence of Tb³⁺and Eu³⁺ ions.9 and 11 can be used as potential blue and red fluorescence materials.The influence of solvate effect on luminescent intensity is also discussed.(4)11 luminescent complexes 12-22 were synthesized based on the use of aromatic dicarboxylic acids and 3-pytpy as mixed ligands.The coordination modes of 3-pytpy were discussed.The influence of the structural features of organic acids(size,shape,flexibility)on the resulting complexes was also investigated.Most of these compounds exhibit excellent luminescent properties,the emission bands locate at the similar positions and the mechanism of luminescence can be assigned into intraligand charge transition(ICT).